Dowsing has in fact not been proven to work. There is instead overwhelming evidence that it does not work better than chance.
Wikipedia sums it up nicely, with citations:
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The motion of such dowsing devices is generally attributed to the ideomotor phenomenon,[7][8][9] a psychological response where a subject makes motions unconsciously. Put simply, dowsing rods respond to the user's accidental or involuntary movements.
The scientific evidence is that dowsing is no more effective than random chance.[10][11] It is therefore regarded as a pseudoscience.
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https://en.m.wikipedia.org/wiki/Dowsing
For an entertaining time, check out the late James Randi and his debunking of dowsing
Wikipedia sums it up nicely, with citations: -- The motion of such dowsing devices is generally attributed to the ideomotor phenomenon,[7][8][9] a psychological response where a subject makes motions unconsciously. Put simply, dowsing rods respond to the user's accidental or involuntary movements.
The scientific evidence is that dowsing is no more effective than random chance.[10][11] It is therefore regarded as a pseudoscience. -- https://en.m.wikipedia.org/wiki/Dowsing
For an entertaining time, check out the late James Randi and his debunking of dowsing